Microsoft's launch of its newest mobile OS, Windows Phone 8, has truly begun in earnest as more details of the Samsung Ativ S were revealed during its San Francisco press conference today. Introduced this past summer during IFA 2012 in Berlin, the Ativ S was the first WP8 handset to be announced.

According to a Samsung rep, there are currently no plans to bring the device to the United States. However, the Ativ S will launch elsewhere globally by the end of November. It'll go head-to-head with other WP8 phones, mostly from Nokia, such as the Lumia 920, 820, and the newly unveiled 822.

Design
The Samsung Ativ S measures 5.40 inches tall and 2.78 inches wide. With a profile of 0.34 inch, it is the thinnest WP8 handset, and its 4.8-inch HD Super AMOLED display earns it the title of the biggest WP8 device as well.

The phone is large and requires a wide grip. It won't fit easily in small jean pockets, but it has a very premium feel to it. Its brushed-metallic aesthetic that's featured on the back plate is attractive and unique, and its audio speaker grill, which stretches across the entire width of the Ativ S' rear, looks promising for ample sound.

During our brief time with the device, we noticed that the screen was bright and responsive. Now that the new Start screen on WP8 handsets fill up the whole screen, the Ativ S makes the most of dynamic live tiles and photos looked vivid and rich.

Features
In addition to its 1.5GHz dual-core processor, the Ativ S packs in a rear-facing 8-megapixel camera with autofocus and an LED flash, and a 1.9-megapixel front-facing camera.

Taking full advantage of new WP8 software capabilities, the handset will house a microSD card and support for NFC (think file-sharing and, soon, payment).

Samsung has also added a very large 2,300mAh battery that should promise longer life, and 1GB of RAM. It'll come in 16GB and 32GB storage versions, and will feature a host of Samsung apps, like the Music Hub and the Media Hub for the U.S. market.

The Ativ S supports HSPA+, not 4G LTE. If the Ativ ever comes to the U.S., HSPA+ connectivity will limit the Ativ to T-Mobile, unless Samsung also releases a model compatible with LTE. The latter is probable, and a common adjustment for handsets with a global reach.

Though we didn't spend a lot of time with it, the phone's performance was zippy -- taking pictures was a snap, and it breezed through navigating the Start screen and application list.

Outlook
As previously noted, U.S. consumers may not see the Ativ S anytime soon (though Microsoft did hint at another Samsung WP8 phone, the Odyssey, which will be available on Verizon this December). That being said, it'll still face tough competition from Nokia's line of WP8 phones, namely the flagship Lumia 920. It, too, has a 1.5GHz dual-core CPU, an HD AMOLED display, NFC, and a microSD card slot.

However, the Ativ S will have its work cut out for it since the 920 has a few key differences that gives the Nokia handset a slight edge. Namely, its unique design has proven itself popular, it has an 8.7-megapixel camera, and it has LTE capabilities. And since the majority of mobile users aren't familiar with Windows Phone in general, the Ativ S will need to heavily depend on the Samsung brand to push it to the top.

About The Author

Jessica Dolcourt reviews smartphones and cell phones, covers handset news, and pens the monthly column Smartphones Unlocked. A senior editor, she started at CNET in 2006 and spent four years reviewing mobile and desktop software before taking on devices.

About The Author

Lynn La is CNET's associate editor for cell phone and smartphone news and reviews. Prior to coming to CNET, she wrote for the Sacramento Bee and was a staff editor at Macworld. In addition to covering technology, she has reported on health, science, and politics.